1. Field of the Invention
The present invention relates to methods of reducing water produced with hydrocarbons from wells, and more particularly, to methods of stimulating and/or completing a well while also reducing water production therefrom.
2. Description of the Prior Art
A variety of methods have heretofore been developed and used for reducing the flow of water produced with hydrocarbons from a subterranean formation. Such methods have generally involved pumping a fluid into the formation which forms a water blocking material therein. For example, U.S. Pat. No. 3,334,689 issued to McLaughlin on Aug. 8, 1967 discloses a water control method wherein an aqueous solution of a polymerizable composition containing a monoethylenically unsaturated acrylate monomer and a cross-linking agent are injected into the portion of a hydrocarbon producing formation from which water is also produced. The monomer and cross-linking agent are caused to form a stable cross-linked gel in the formation to thus reduce the water permeability of the formation and thereby terminate or at least decrease the rate of flow of water from the formation.
U.S. Pat. No. 5,358,051 issued to Rodrigues on Oct. 25, 1994 discloses a method of forming a gel in the water producing portion of a subterranean formation which also includes hydrocarbons to reduce or prevent the production of water from the formation. In accordance with the method, a self cross-linking monomer selected from hydroxy unsaturated carbonyl compounds is polymerized in the formation by a suitable initiator.
Other methods using various other water blocking agents including cross-linked gels, cement compositions and various polymers have been utilized to reduce the production of water from subterranean formations producing both hydrocarbons and water. However, such methods usually only minimize the water production in that the methods are often not utilized until after the water has invaded the oil zones in the formation and has become a severe problem due to the cost of separation and disposal.
Thus, there is a need for improved methods of economically reducing or preventing the production of water with hydrocarbons from a subterranean formation which can be implemented at an early time in the hydrocarbon producing life of the formation.